1. Field of the Disclosure
This disclosure generally relates to an interactive device and, more particularly, to an optical navigation device.
2. Description of the Related Art
The conventional optical mouse generally includes a light source, an image sensor and a processing unit, and is configured to be operated on a work surface by a user. The light source is configured to illuminate the work surface. The image sensor receives reflected light from the work surface to output image frames. The processing unit is configured to calculate a displacement of the optical mouse with respect to the work surface according to the image frames outputted from the image sensor, e.g. according to the correlation between the image frames.
In the above conventional optical mouse, when the processing unit identifies that an image quality of the image frames captured by the image sensor is poor, the displacement is not outputted so as to avoid cursor jitter or operating error. For example, when the optical mouse is lifted from the work surface by the user, the image quality is degraded. However, the image quality is generally degraded by the interference from noise or ambient light such that the processing unit may not be able to correctly output desired trace of the mouse and furthermore may not be able to enter a sleep mode. In other words, an expected accuracy can not be achieved by determining whether to stop outputting the displacement only according to the image quality.
According, the present disclosure further provides an optical navigation device that can effectively eliminate the interference from noise and ambient light and an operating state can be accurately calculated even thought it is operated on a work surface having a low reflectance so as to improve the operating accuracy of the optical navigation device.